1. Field of the Invention
The invention relates in general to a package structure and a manufacturing method thereof, and more particularly to a package structure whose packing material layer is projected to a lateral surface and a manufacturing method thereof.
2. Description of the Related Art
The package structure prevents the semi-conductor chip from having short-circuits or other problems caused by moisture, collision or metallic particles. Various semi-conductor chips are developed and so are the packaging processes.
Referring to FIGS. 1A˜1D, a conventional manufacturing process of package structure is shown. Firstly, as shown in FIG. 1A, a substrate 110 having a top surface 110a and a number of solder pads 110b is provided. The solder pads 110b are disposed on the top surface 110a. Next, as shown in FIG. 1B, a chip 120 having an active surface 120a and a number of connecting pads 120b is disposed on the substrate 110. The connecting pads 120b are disposed on the active surface 120a and correspond to the solder pads 110b. Then, as shown in FIG. 1C, a wiring bonding process is applied. The connecting pads 120b on the chip 120 and the solder pads 110b on the substrate 110 are wiring bonded by a number of bonding wires 130, such that the micro-electronic elements and the circuits thereof inside the chip 120 are electrically connected to the substrate 110 via the connecting pads 120b, the bonding wires 130 and the solder pads 110b. Next, as shown in FIG. 1D, a molding process is applied. A molding compound 140 is formed on the chip 120. The molding compound 140 prevents the connecting pads 120b, the bonding wires 130, and the solder pads 110b from being oxidized due to moisture and prevents the chip 120 from being damaged due to collision. Thus, a conventional package structure 100 is formed.
Referring to FIGS. 2A˜2C, a molding process of FIG. 1D is shown. As shown in FIG. 2A, during the molding process, the substrate 110 and the chip 120 are retained by a top mold 151 and a bottom mold 152. As shown in FIG. 2B, the top mold 151 and the bottom mold 152 are coupled to form a receiving space 150a, wherein the chip 120 is positioned in the receiving space 150a. Next, the receiving space 150a is filled with the molding compound 140. The molding compound 140 is a fluid before having been solidified. Then, as shown in FIG. 2C, the molding compound 140 is thermo-set, and the top mold 151 and the bottom mold 152 are removed to form the package structure 100 of FIG. 1D. The fringe of filling the molding compound 140 is applied from the chip 120 to the edge of the substrate 110.
However, the shape of the molding compound 140 is subject to the shape of the top mold 151 and the shape of the bottom mold 152. Since the non-solidified molding compound 140 is a fluid, the receiving space 150a formed by the top mold 151 and the bottom mold 152 has to take the flow path of the molding compound 140 into consideration. Therefore, both the size and the shape of the molding compound 140 are subject to certain restrictions.